  -75  -77   -1 -272  -24  -49  -34  -96  -20 -123
   -1 -140  -32  -45  -22 -124   -1  -43 -108 -176
   -1  -71  -18  -80  -55  -39   -1 -156   -1  -59
  -26  -72   -1  -61  -18 -192  -51  -33   -1  -92
   -1  -31  -22  -92  -16  -81   -1  -56  -20  -45
  -14 -112   -1  -25  -39  -48   -1  -41   -1  -68
  -16  -21   -1  -60  -12  -19  -14  -80   -1  -31
   -1  -32  -27  -15  -10  -44   -1  -13  -10  -24
   -1  -21   -1  -32   -8   -9   -1  -16   -1   -7
   -6  -12   -1   -5   -1   -4   -1   -1    0    0
    0    1    1    4    1    5    1   12    6    7
    1   16    1    9    8   32    1   21    1   24
   10   13    1   44   10   15   27   32    1   31
    1   80   14   19   12   60    1   21   16   68
    1   41    1   48   39   25    1  112   14   45
   20   56    1   81   16   92   22   31    1   92
    1   33   51  192   18   61    1   72   26   59
    1  156    1   39   55   80   18   71    1  176
  108   43    1  124   22   45   32  140    1  123
   20   96   34   49   24  272    1   77   75  140

D(10^1)/7 = 1
D(10^2)/7 = 20
D(10^3)/7 = 300
D(10^4)/7 = 4000
D(10^5)/7 = 50000
D(10^6)/7 = 600000
D(10^7)/7 = 7000000
D(10^8)/7 = 80000000
D(10^9)/7 = 900000000
D(10^10)/7 = 10000000000
D(10^11)/7 = 110000000000
D(10^12)/7 = 1200000000000
D(10^13)/7 = 13000000000000
D(10^14)/7 = 140000000000000
D(10^15)/7 = 1500000000000000
D(10^16)/7 = 16000000000000000
D(10^17)/7 = 170000000000000000
D(10^18)/7 = 1800000000000000000
D(10^19)/7 = 19000000000000000000
D(10^20)/7 = 200000000000000000000